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Publication numberUS4707896 A
Publication typeGrant
Application numberUS 06/927,593
Publication dateNov 24, 1987
Filing dateNov 5, 1986
Priority dateNov 5, 1986
Fee statusLapsed
Also published asCA1279987C, EP0266766A2, EP0266766A3
Publication number06927593, 927593, US 4707896 A, US 4707896A, US-A-4707896, US4707896 A, US4707896A
InventorsLyles H. Sowell
Original AssigneeE. I. Du Pont De Nemours And Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Crimper discharge regulation
US 4707896 A
Abstract
A gate/loading arrangement which balances applied gate force betweem the edges of tow being crimped in a stuffer box crimper. A single hinged gate has been replaced with two or three equal sized gates and force is applied to the gates from an air cylinder through a pivotal linkage.
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Claims(9)
I claim:
1. In a stuffer box crimping process in which yarn is forced into a crimping chamber and the outlet of the chamber is provided with a single hinged gate having force applied thereto by fluid pressure means, the improvement of which comprises: dividing said single gate into a plurality of hinged gates positioned side-by-side across the width of said outlet and balancing any unequal force applied to said gates due to variations in thickness of yarn exiting said outlet by transferring force among gates by means of a linkage connected between said gates and said fluid pressure means.
2. The method of claim 1 wherein said gate is divided into two hinged gates of equal size.
3. The method of claim 1 wherein said gate is divided into three hinged gates of equal size.
4. A yarn crimping apparatus comprising a crimping chamber having an inlet and an outlet;
means located adjacent the inlet of the crimping chamber for forcing yarn into the chamber;
a plurality of hinged gates in a side-by-side relationship associated with the outlet of the crimping chamber to regulate the discharge of yarn from the chamber;
means for applying force to said gates; and
means for balancing any unequal force applied to said gates due to variations in the thickness of the yarn exiting the outlet of the crimping chamber.
5. The apparatus of claim 4, wherein said means for balancing any unequal force due to variations in thickness of the yarn exiting the outlet of the crimping chamber is a pivoting linkage connected between said hinged gates and said means for applying force to said gates.
6. The apparatus of claims 4 or 5 wherein there are two gates.
7. The apparatus of claim 6 wherein said gates are of equal size.
8. The apparatus of claims 4 or 5 wherein there are three gates.
9. The apparatus of claim 7 wherein said gates are of equal size.
Description
BACKGROUND OF THE INVENTION

This invention relates to stuffer box crimping of yarn, and more particularly, it relates to a method and apparatus for controlling crimp.

Stuffer box crimpers are well known and have been widely employed for crimping filament strands, including for example, yarns, tows and threads.

In the case of tow, formed of several ropes of yarn, crimp level is controlled by the amount of force applied to the tow band by a single hinged gate associated with the outlet of the crimping chamber. A problem may arise because the thickness of the tow band entering the crimper varies across the width of the band due to interactions between the ropes which make up the tow.

The two edges of the tow band experience the greatest variations due to contact with guides employed to position the tow band ahead of the crimper. While one edge may be consistently thicker than the other, a more common occurrence is the periodic thickening of one edge with a simultaneous thinning of the opposite edge. Either of these conditions results in poor crimp uniformity across the tow band width. In severe cases operability (crimper jams) becomes a major problem. This occurs when the thick edge carries most of the gate force causing the thin edge to become slack.

SUMMARY OF THE INVENTION

An improved process and apparatus has been developed which continuously balances the applied gate forces between the edges of the tow being crimped. The single hinged gate is divided into a plurality of hinged gates and any unequal force applied to the gates due to variations in the thickness of the tow exiting the crimping chamber is balanced by transferring forces between the gates by means of a pivoting linkage located between the gates and the source of force applied to the gates.

The gate arrangement may be a double or triple gate arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the invention with two hinged gates.

FIG. 2 is a perspective view of another embodiment of the invention with three hinged gates.

Referring to the drawings, a continuous tow 10 is fed by means of rollers 12, 14 into the inlet 15 of stuffer box 16 comprising a crimping chamber and a regulation means at the outlet 17 of the stuffer box in the form of two gates 18, 20 of equal size hinged to stuffer box 16 via pin 21 (FIG. 1) or three equal sized hinged gates 22, 24, 26 (FIG. 2).

In FIG. 1, an air cylinder 28 applies a force as desired through pivoting linkage 30 against gates 18, 20. The pivoting linkage 30 includes a bar 32 and pin supports 34, 36, 38 fixed to gate 18, gate 20 and cylinder rod 29, respectively. Bar 32 is loosely pinned at its ends in pin supports 34, 36 and at its center in pin support 38 attached to cylinder rod 29. Air cylinder 28 is a double acting cylinder which applies pressure through rod 29 against gates 18,20 through linkage 30. Compressed air is supplied from a source indicated by arrow 40 through pressure control valves 42, 43 via pipes 44, 45 to cylinder 28.

In operation, the pressure is manually set at the top of cylinder 28 by adjusting controller 43, and at the bottom of cylinder 28 by controller 42, then as either gate 18 or 20 is forced open by tow 10 which has a thicker than normal portion along its edge, the reaction force applied to the gate will be transferred via the pivoting bar 32 to the other gate. This results in a more uniform application of gate loading to both halves of the tow regardless of thickness. The crimped tow 11 emerging from the stuffer box 16 falls into a collection means (not shown).

In FIG. 2, like elements are numbered the same as in FIG. 1 and in this embodiment three gates are used, i.e., 22, 24, 26 and the pivoting linkage is constructed to have pin supports 34', 36', and 38' fixed to gates 22, 24 and 26, respectively. The bar 32 is loosely pinned at its ends to pin supports 34' and 36' and at its center to pin support 38', by pins 50, 54, 52, respectively. The air cylinder rod 29 is pinned to pin support 38' by means of loosely fitted pin 56.

This embodiment with three gates, hinged at pin 21 which passes through stuffer box 16, has the ability to give more or less loading to the side gates 22, 24 versus the center gate 26 by shifting the relative location of pins 50 and 54 with respect to pin 52.

For example, if more loading is desired on gates 22, 24 than on gate 26 then locations of pins 50, 54 relative to location of pin 52 would be placed to position gates 22, 24 forward of gate 26. Conversely, if less force is desired on gates 22, 24 than on gate 26, locations of pins 50, 54 relative to pin 52 would be placed to position gates 22, 24 behind gate 26.

In a series of runs on four different polyester products fed into a stuffer box crimper under substantially similar conditions for each product, a comparison of crimp uniformity using a single hinged gate versus two hinged gates (FIG. 1) was made using the standard deviation (means square of successive differences) of the crimps per inch. The results are shown in the table below.

______________________________________Product    Du Pont    Standard DeviationDenier/filament      Type Polyester                   Single gate                             Two gates______________________________________12.0       776          0.884     0.76612.0       768          0.695     0.596 3.0        35          0.744     0.695 1.5       811          1.061     0.875______________________________________

In each case, the standard deviation of crimps per inch for the two gate arrangement is less than that of the single gate thus confirming a more uniform level of crimp.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2514557 *Aug 7, 1948Jul 11, 1950Alexander Smith & Sons CarpetCrimping apparatus
US3231958 *Jan 20, 1964Feb 1, 1966Du PontApparatus for guiding a textile tow
US3234626 *Oct 28, 1963Feb 15, 1966Monsanto CoApparatus for hot and cold crimping of textile filaments
US3241213 *Jan 13, 1964Mar 22, 1966Monsanto CoQuick-opening stuffing box
US3345719 *Jun 22, 1964Oct 10, 1967Glanzstoff AgApparatus for continuous production of crimped filaments
US3406436 *Nov 30, 1965Oct 22, 1968Allied ChemCrimping process
US3553802 *Apr 4, 1968Jan 12, 1971Techniservice CorpStrand crimping
US3639955 *Dec 19, 1969Feb 8, 1972Vepa AgApparatus for crimping groups of synthetic filaments
US3800373 *Aug 4, 1971Apr 2, 1974Vepa AgDevice for crimping groups of synthetic filaments
US3859695 *Jan 5, 1973Jan 14, 1975Phillips Petroleum CoStuffer box control
US4547934 *Jan 31, 1984Oct 22, 1985Phillips Petroleum CompanyFor producing crimped staple fibers with uniform cohesion levels
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5020198 *Aug 10, 1988Jun 4, 1991Filter Materials Ltd.Crimped textile fibers and stuffer box apparatus and methods for crimping textile fibers
US5316827 *Mar 7, 1991May 31, 1994Filter Materials LimitedTobacco filters
US6351877May 31, 2000Mar 5, 2002Eastman Chemical CompanySynthetic fiber crimper, method of crimping and crimped fiber produced therefrom
Classifications
U.S. Classification28/250, 28/263
International ClassificationD02G1/12, D02G1/02, D02J1/22
Cooperative ClassificationD02G1/12
European ClassificationD02G1/12
Legal Events
DateCodeEventDescription
Mar 12, 1996FPExpired due to failure to pay maintenance fee
Effective date: 19951129
Nov 26, 1995LAPSLapse for failure to pay maintenance fees
Jul 4, 1995REMIMaintenance fee reminder mailed
Apr 25, 1991FPAYFee payment
Year of fee payment: 4
Jan 20, 1987ASAssignment
Owner name: E.I. DU PONT DE NEMOURS AND COMPANY, WILMINGTON, D
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:SOWELL, LYLES H.;REEL/FRAME:004658/0742
Effective date: 19861027
Owner name: E.I. DU PONT DE NEMOURS AND COMPANY, A CORP OF DE.
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SOWELL, LYLES H.;REEL/FRAME:4658/742
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SOWELL, LYLES H.;REEL/FRAME:004658/0742